Field of the Invention
The invention relates to an internal manipulator for pipes which has devices for treating, in particular, testing pipe walls, the manipulator having two carriages provided with rolling bodies which are movable towards a pipe wall by antagonistically acting drives, and a rotary mounting or bogie which is arranged between and mounted on the carriages so as to be rotatable about a common system axis extending in the direction of travel of the manipulator, the rotary mounting or bogie having an axially displaceable holder formed with at least one radial arm whereon at least one stop body, respectively, and one treatment unit, respectively, are arranged in a radially displaceable manner, the rotary mounting or bogie having two radial flange plates, between which a rotary drive for the rotary mounting or bogie, a servomotor of an axial drive for the holder of the treatment units, a screw spindle of the axial drive, and a guide rod for the holder having the treatment units are arranged so that the axes thereof extend parallel to the system axis.
Such manipulators serve to treat pipelines which are inaccessible, whether for spatial reasons or due to heat, pressure and radiation. Manipulators of this type may be constructed to be self-propelled, but they may also be pulled or pushed and be part of a series arrangement of a whole group of pipe vehicles. The expression "treatment" refers to all operations which are concerned with the condition of the pipeline to be negotiated or traversed, whether this is an inspection wherein the actual visual condition is being recorded, an ultrasonic examination of welds, mechanical treatment operations such as welding or grinding, or coating operations by which, for example, the inner wall of a respective pipe is to be provided with a protective coating. Particularly in reactor construction, extremely stringent requirements which the function of such an internal manipulator for pipes must satisfy are imposed upon the condition of pipelines and on the documentation of this condition.
The published German Patent Document DE 34 12 519 C2 discloses an internal manipulator for pipes which is of the general type mentioned at the introduction hereto, wherein the rotary drive for the rotary mounting or bogie, the servomotor of the axial drive for the holder of the treatment units, the screw spindle of the axial drive, and a guide rod for the holder with the treatment units are accommodated inside a quadrant of the cross-sectional are of the manipulator. In this regard, the supporting body of the rotary mounting or bogie is formed of a hollow half-cylinder wherein a holder is accommodated, a single radial arm having a stop body and a total of eight treatment units being fastened to the holder. In this case, the holder with the treatment units fills essentially two further quadrants of the manipulator cross section. The conventional construction or solution is preferred for negotiating or traversing pipelines having an inside diameter of more than 200 mm.
In connection with increasing safety requirements, it has become necessary to develop internal manipulators of pipes which are also used in conjunction with smaller pipeline diameters, for example, down to about 80 mm inside diameter.